style the live libraries table + add Language column

- libraries.md: render the live lib list as a 3-column table (Library /
  What it does / Language), wrapped in .rt-lib-table so it picks up
  explicit styling (Material only auto-styles markdown tables, not
  innerHTML-injected ones — that's why it rendered bare before).
- extra.css: branded table (navy header, blue borders, hover rows,
  code-styled linked names) and a blue Language badge.

Verified in-browser against real Gitea API data (14 repos fetched,
handbook denylisted -> 13 libs): table renders sorted with language
badges, matches the theme. Live load on prod still needs Gitea CORS
(app.ini [cors] ALLOW_DOMAIN = the docs origin).

Signed-off-by: disqualifier <dev@disqualifier.me>

docs/libraries.md

@@ -89,12 +89,17 @@ Pin a tag in your dependencies — never an unpinned branch:
     var rows = libs.map(function (r) {
       var url = r.html_url || (REPO_BASE + "/" + r.name);
       var desc = r.description ? escapeHtml(r.description) : "<em>No description.</em>";
+      var lang = r.language
+        ? '<span class="rt-lang">' + escapeHtml(r.language) + "</span>"
+        : '<span class="rt-lang rt-lang--none">—</span>';
       return '<tr><td><a href="' + escapeHtml(url) + '"><code>' +
-        escapeHtml(r.name) + '</code></a></td><td>' + desc + '</td></tr>';
+        escapeHtml(r.name) + "</code></a></td><td>" + desc +
+        "</td><td>" + lang + "</td></tr>";
     }).join("");
     el.innerHTML =
-      '<table><thead><tr><th>Library</th><th>What it does</th></tr></thead>' +
-      '<tbody>' + rows + '</tbody></table>';
+      '<div class="rt-lib-table"><table>' +
+      "<thead><tr><th>Library</th><th>What it does</th><th>Language</th></tr></thead>" +
+      "<tbody>" + rows + "</tbody></table></div>";
   }
 
   function fail() {